Countermass propulsion system
The invention relates to a countermass propulsion system for shoulder-launched munitions, recoilless rifles, rockets and similar class weapon systems, fired from an enclosure and utilizing a Davis Gun propulsion system by accelerating a projectile in one direction and a countermass in the opposing direction to minimize recoil, light signature and acoustic signature of the weapon system.
1. A countermass propulsion system for an FFE recoilless weapon, said system comprising:
a pressure vessel having a muzzle end and a breach end,
wherein the vessel contains a projectile disposed at the muzzle end and a countermass disposed at the breach end;
a propellant charge, disposed between the projectile and the countermass;
a rupture disk disposed behind an igniter assembly and at a forward end of the countermass;
and a projectile retention means that is connected to the projectile and the rupture disk.
2. The countermass propulsion system of claim 1 , said system having a minimized acoustic signature that is a sound pressure level (SPL) less than 175 dB as measured at a location 20 inches forward from the breach of the countermass propulsion system and 7 inches off of centerline of the weapon in the average of two locations, while being fired from a 15 foot ×12 foot ×7 foot enclosure.
3. The countermass propulsion system of claim 2 , wherein the acoustic signature is an SPL of no more than 173.5 dB.
4. The countermass propulsion system of claim 2 , wherein the acoustic signature is an SPL of no more than 170 dB.
5. The countermass propulsion system of claim 2 , said system having a minimized recoil energy in the range of 0-16 ft·lbs.
6. The countermass propulsion system of claim 5 , said system having a minimized recoil energy in the range of 0-5 ft·lbs.
7. The countermass propulsion system of claim 6 , said system having a minimized recoil energy in the range of 0-2 ft·lbs.
8. The countermass propulsion system of claim 2 , said system having a minimized recoil energy in the range of 0-2 ft·lbs., wherein the composition of the rupture disk is selected from the group consisting of at least one or more of a stainless steel and an austenite nickel-chromium-based superalloy.
9. The countermass propulsion system of claim 1 , wherein said projectile retention means comprises one or more of a tensile rod and threads, tensile links, pins, threads, or combinations thereof.
10. The countermass propulsion system of claim 1 , wherein said projectile retention means comprises a breakbolt.
11. The countermass propulsion system of claim 5 , wherein said projectile retention means comprises a breakbolt and the breakbolt is configured to release the projectile after a maximum tensile load of 1,050 to 7,000 lbf is reached.
12. The countermass propulsion system of claim 1 , further comprising an aft seal disposed behind the countermass at the breach end of the vessel.
13. The countermass propulsion system of claim 1 , wherein said rupture disk is configured to remain closed during operation of the system to a predetermined point in time, thereby preventing the countermass from being exposed to combustion gases in the pressure vessel.
14. The countermass propulsion system of claim 11 , wherein the rupture disk is configured to rupture and open at a static pressure in a range of 300 to 2,000 psi.
15. The countermass propulsion system of claim 14 , wherein the rupture disk is configured to rupture and open at a static pressure in a range of 1,000 to 1,500 psi.